1. Field of the Invention
The present invention relates to a wire saw and a workpiece slicing method thereof, and more particularly to a wire saw and a workpiece slicing method thereof for slicing brittle materials such as silicon, glass and ceramics.
2. Description of the Related Art
When the wire saw slices a single crystal material such as silicon into wafers, the single crystal material must be tilted by a predetermined angle with respect to a plane including a wire row of the wire saw so that the face of the sliced wafer can be a desired crystal face.
In the conventional wire saw, tilting equipment, which is integrated with a workpiece feed table, adjusts a tilt angle of the workpiece. The tilting equipment supports the workpiece so that the workpiece can swing horizontally and vertically with respect to the plane of the wire row. An operator manually adjusts the tilt angle of the workpiece based on the previously-obtained data relating to the crystal orientation of the workpiece.
Since the tilting operation in the wire saw has to be done in a limited space, the operation is extremely difficult. In addition, the operation takes time, and the slicing cannot be efficiently performed.
In the conventional method of adjusting the tilt angle of the workpiece, if an error takes place when the workpiece is attached to the tilting equipment, the error will not be noticed. Thus, inferior wafers will be manufactured.
Furthermore, the conventional wire saw slices only one workpiece per slicing. For this reason, if the workpiece is much shorter than the width of the wire row, much of the wire row can not contribute to the slicing, and the manufacturing efficiency is lowered.